One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,12)(8,10)(9,11)(13,14,20,24)(15,25,16,22)(17,18,23,19)(21,27,26,28)(1,2,3,4)(13,15,19,28,20,16,18,27)(14,21,23,25,24,26,17,22)(5,7,9,8)(6,10,11,12)(13,16)(14,22)(15,20)(17,21)(18,27)(19,28)(23,26)(24,25)(5,8,9,7)(6,10,11,12)(13,17)(14,18)(15,26)(16,21)(19,24)(20,23)(22,27)(25,28)(13,18,20,19)(14,23,24,17)(15,27,16,28)(21,25,26,22)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.